Gov. Charlie Crist launched what amounts to a nuclear attack in Republican politics during his FOX News Sunday showdown with Marco Rubio.

Crist labeled Rubio, the former House speaker, a tax raiser.

In a back and forth about each other's record on tax issues, Crist singled out Rubio's failed 2007 plan that would have eliminated property taxes for many Floridians in exchange for an increase to the state sales tax.

The tax swap "would have been a massive tax increase," Crist said during the March 28, 2010, U.S. Senate debate. "In all due respect to the speaker, you've just got to tell the truth to people. And that's really what this is all about."

Rubio contends that the tax swap would have been a huge, net tax cut. And that the plan was supported by former Gov. Jeb Bush.

Would it have been a tax cut? Or a tax hike?

Let's take a look.

In his first months as speaker in early 2007, Rubio proposed a fundamental change in Florida's tax structure. The proposal would scratch property taxes on all primary residences. In its place, the state sales tax would be increased by 2.5 cents per dollar -- subject to voter approval.

A House analysis originally said the swap would save taxpayers a total of $5.8 billion in the first year, which certainly is contrary to Crist's claim.

But whether you saved money or spent more money at the end of the year likely depended on your individual circumstances. Back in 2007, the St. Petersburg Times ran calculations under Rubio's proposal for both homeowners and renters.

The homeownersA family of four with an annual income of $64,280. Home value: $241,100

CURRENTProperty tax bill in Tampa: $5,061.06Sales taxes paid: $951

PROPOSEDProperty tax bill in Tampa: $0Sales taxes paid: $1,290

Under Rubio's plan, these homeowners would have paid $4,722 less in state taxes, the Times found. Contrast that with renters:

The rentersA family of two with an annual income of $46,914

CURRENTRent: $851Sales taxes paid: $691

PROPOSEDRent: $851Sales taxes paid: $937

Under Rubio's plan, these renters would pay an additional $246 a year in taxes. The rental property owners also would still have to pay property taxes, meaning rent wouldn't be affected.

"He talked about it being a swap, and it would be a swap because those who owned their home wouldn't have to pay a tax anymore," Crist said during the debate. "Forty percent of my fellow Floridians are renters. It would not have applied to them at all. All they would have enjoyed is his tax increase."

Rubio responded: "The renters would have had an opportunity to buy now because the exorbitant taxes that we pay on property in Florida would not have gone up."

Conversely Rubio pointed out that the increased sales tax would bring more revenue into the state from non-resident visitors. If tourists contribute more, he said, Floridians contribute less.

Rubio's proposal got the seal of approval from Grover Norquist, president of Americans for Tax Reform and a Rubio supporter. In 2007, he wrote legislators saying Rubio's tax swap proposal amounted to a net tax cut.

"Speaker Rubio’s proposal is a net tax cut, thus a vote for the proposal would not constitute a violation of the Taxpayer Protection Pledge," Norquist wrote. "All taxpayers of Florida would reap the benefits of a lower tax burden and significant spending restraint on the state as well as on the local level."

A later House study said the sales tax increase would generate $9.3 billion in exchange for eliminating $15.8 billion in property taxes. (Here's a House analysis of the swap, which was combined with other tax initiatives).

"Only in Tallahassee could a bunch of politicians declare that a $7 billion net tax savings is a tax increase," Rep. Adam Hasner, R-Delray Beach, told the Palm Beach Post.

Crist spokeswoman Andrea Saul noted that Rubio himself said the tax swap was a tax increase during the March 28, 2010, debate. According to transcripts, Rubio said: "Well, let me tell you about that supposed program to raise taxes that he keeps talking about. It was probably the largest tax increase in Florida's history. It would have eliminated property taxes for all sorts of people. And it was supported by (none other) than Jeb Bush."

Based on the statements that surround Rubio's "largest tax increase" line, it seems reasonable to us that he meant to say decrease.

Back to Crist. He said Rubio's tax swap proposal "would have been a massive tax increase." At its most basic level, Rubio's proposal was a tax increase and a tax decrease. The state sales tax would go up, and the property taxes would go down. On the micro level, some people would pay more and others would pay less. At the macro level, two different studies said Floridians would have paid less -- between $5.8 billion and $6.5 billion. While generally we are leery about tax impact projections, there is no suggestion Rubio's plan would have resulted in a tax increase statewide and certainly not a "massive" one as Crist suggests. As such, we rate Crist's claim False.

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